A anticarcinogenic slow release injection carrying platinum compounds and a synergist thereof is composed of slow release microspheres and a dissolvant, wherein, the slow release microspheres comprise anticancer active components and a slow release adjuvant, and the dissolvant is a special dissolvant containing a suspending agent. The anticancer active component comprises platinum compounds such as sunpla, dicycloplatin, eptaplatin, (cis-amminedichloro(2-methylpyridine) platinum, camphoramine chloroacetic platinum or picoplatin, and the like, and a cytotoxic drug selected from a phosphoinositide 3-kinase inhibitor, pyrimidine analogue and/or a DNA repair enzyme inhibitor; the slow release adjuvant is biocompatible macromolecules such as polylactic acid and copolymer thereof, polyethylene glycol, carboxyl end polylactic acid copolymer, copolymer of dienoic fatty acid and sebacic acid, poly (erucic acid dimer-sebacic acid), poly (fumaric acid-sebacic acid), polifeprosan, polylactic acid, EVAc, and the like, and the suspending agent has the viscosity of 100cp-3,000cp (at the temperature of 20-30 DEG C) and is selected from sodium carboxymethyl cellulose, and the like. The slow release microspheres can also be made into a slow release implant. The slow release injection is injected or placed in tumors or around the tumors, which can improve the curative effects of non-operative therapies such as radiotherapy, chemotherapy, and the like.